Journal of Ethnopharmacology 94 (2004) 129–133 Central nervous system effects of the crude extract of Erythrina velutina on rodents M.C. Dantas, F.S. De Oliveira, S.M. Bandeira, J.S. Batista, C.D. Silva, Jr., P.B. Alves, A.R. Antoniolli, M. Marchioro ∗ Laboratório de Neurofisiologia, Departamento de Fisiologia, Universidade Federal de Sergipe, São Cristóvão-SE 49100-000, Brazil Received 17 February 2001; received in revised form 6 May 2004; accepted 10 May 2004 Available online 26 June 2004 Abstract The aqueous extract (AE) of Erythrina velutina prolonged the sleep duration induced by sodium pentobarbital (control: 6.4 ± 1.2 min; extract 10 mg/kg, 47.1 ± 3.9 min; extract 100 mg/kg, 109.4 ± 7.2 min; F = 243, P < 0.001). In the open field, the extract at the doses of 10 and 50 mg/kg did not changed the number of crossings, rearings nor groomings. On the other hand, at the dose of 200 mg/kg it reduced the number of crossings (q = 6.25, P < 0.05) and groomings (q = 3.91, P < 0.05). When exposed during three consecutive days to the open field, the control animals showed habituation for crossings (F = 17.56, P < 0.001) and rearings (F = 14.01, P < 0.001). The same was not true for animals treated with 10 mg/kg of the extract (crossings: F = 3.59, P > 0.05; rearings: F = 3.62, P > 0.05). At the same dose, the extract blocked the acquisition of foot shock memory (P = 0.9219) when compared to the control values (P = 0.0078). Our data showed that the crude extract of Erythrina velutina at lower doses interferes with mnemonic process for different tasks, while at higher doses, the sedative and neuromuscular blocking actions are the main effects. © 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Erythrina velutina; Central nervous system; Open field; Memory 1. Introduction Erythrina velutina Willd is a tree measuring from 6 to 10 m, popularly known in Brazil as “mulungu”. It is very common at the coast region of all north and northeast Brazil- ian states. Mulungu is well known for its sedative proper- ties among the population. The genus Erythrina is cited in Brazilian folk medicine for the treatment of central nervous system (CNS) illness, specially the species Erythrina ve- lutina in the northern and Erythrina mulungu in the southern regions of the country. The stem bark of the plant is recom- mended for nervous system excitation, sleepiness, convul- sions and nervous coughs. For internal administration the powder (12 g/day), infusion or decoction (1–2 cups/day) or the fluid extract (1–4 ml/day) are normally used (Teske and Trentini, 1995; Matos, 1997). Despite its common use in folk medicine, most of the scientific work on the genus refers to isolation and characterization of alkaloids and flavonoids ∗ Corresponding author. Tel.: +55 79 2126646; fax: +55 79 2126660. E-mail address: march@ufs.br (M. Marchioro). (Kòbaiashi et al., 1997; Telikepalli et al., 1990; Hegde et al., 1997), with very few studies on pharmacological effects. Among the scientific studies with Erythrina extracts, prepared from different parts of the plant, the curare-like effect has long been known (Lehman, 1937). The dihydro- -erythroidine is one of the most potent curare-like com- pounds isolated from Erythrina (Megirian et al., 1995) and it is also a potent antagonist of neuronal nicotine acetyl- choline receptors (Williams and Robinson, 1984). Decker et al. (1995) found that erysodine, another Erythrina al- kaloid, is even more potent and selective than dihydro-- erythroidine in blocking neuronal nicotine acetylcholine receptors. More recently, Gar´ ın-Aguilar et al. (2000) de- scribed an anti-aggressive effect of alkaloid fractions from Erythrina americana in rats; Saidu et al. (2000) found an- tiplasmodial, analgesic and anti-inflammatory properties from the aqueous extract (AE) of Erythrina senagalensis and Onusic et al. (2002), using the elevated T-maze and the light–dark transition models described an anxiolitic effect of the water–alcohol extract from the inflorescences of Ery- thrina mulungu. Our laboratory proposed a possible interac- tion of the Erythrina velutina extract with ATP-dependent K + channels from rat vas deferens (Santos et al., 2000). 0378-8741/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.jep.2004.05.007